Unit 2- Materials: Structure and Uses

Section 2. A –

Why we use what we do

Do Now Read pages. 108-109

What kind of coin would you like to have?

Objectives 1. SWBAT define properties and changes. 2. SWBAT distinguish between physical

and chemical changes and classify examples of each.

3. SWBAT differentiate between metals, non metals, and metalloids and their locations on the period table.

Wkst – U2A1, HW pg 130 (1-6)

2.A.1 Properties make the difference What are some materials people of the past

have used as currency? What makes a material suitable or useable

to produce coins? How important is appearance or cost?

Physical Properties Characteristics that distinguish elements

from other things Ex. Color, density, odor… Can be observed without altering chemical

structure

Chemical Property Describes how the element reacts with

other elements or substances

Chemical vs. Physical Changes

Chemical Change Physical Change

-substance changes into one or more NEW substances

EX-

-Appearance can change although chemical structure remains intact

EX-

Example 1 Iron RUSTING:

Observing a chemical change can often mean the formation of a gas or solid

Thermal energy can be given off or absorbed

p.111- Developing Skills Consider the statement: Copper

compounds are often blue in color. Does this statement describe a physical or chemical property? Why?

p. 111 – Developing Skills Consider this statement: Oxygen gas

supports the burning of wood. Does this statement refer to the physical or chemical property of oxygen gas? Explain.

Answer Burning or combustion of wood- involves a

chemical reaction Wood and oxygen (reactants) change into

ash, carbon dioxide and water vapor.

Do Now List at least one chemical property and one

physical property

Objectives 1. SWBAT distinguish between physical

and chemical changes and classify examples of each.

Think-Pair-Share Pg 112 #1-9

Complete WKST U2A1 HW

A.3 Properties Matter: Designing the Penny 1. Cost

A. Cost of the production of the penny must be matched by it’s face value ($0.01)

B. Early 1980s Copper became too expensive and Zinc replaced it

C. In 1943, during WWII, Zinc plated steel pennies (quickly corroded)

A.3 Properties Matter: Designing the Penny 2. Solution

Post 1982 pennies – 97.5% Zinc Copper coating a Zinc Core

A.4. Chemical Elements Elements are classified in three major

groups: Metals Nonmetals Metalloids

Take out your PTOE to color in the different sections

Periodic Trends

Transition Metals

Physical Properties of Metals Malleability Ductility Luster Heat conductors and

electrical conductors Typically reacts with

acids Ex. Iron (Fe), tin (Sn),

zinc (Zn), and copper (Cu)

Properties of Nonmetals

Dull in appearance Brittle Do not conduct electricity Ex. Carbon (C) and Oxygen (O)

Metalloids Properties of metals and nonmetals

Ex. Silicon (Si) and Germanium (Ge)

Do Now List the following as a chemical or physical

change 1. A piece of wood burns to form ash. 2. Water evaporates into steam. 3. A piece of cork is cut in half. 4. A bicycle chain rusts. 5. Food is digested in the stomach. 6. Water is absorbed by a paper towel. 7. A change in color

Objectives 1. SWBAT review physical and chemical

changes 2. SWBAT identify trends in the periodic

table.

Objectives SWBAT identify properties of metals,

nonmetals, or metalloids SWBAT create their own trends in the

periodic table.

Periodic Table Used to organize elements based on their

properties

Dimitri Mendeleev Created a periodic table of elements based

on: 1. Atomic Weights 2. “Combining Capacity”

Now you Try Turn to page 119 and follow steps #1-6 Try to create your own periodic table based

on several different properties

Transition Elements/Metals

Periodic Trends Periods: horizontal rows Groups/Families: vertical columns

Trends in Periodic Families

Alkali Metal Family: Group 1 Highly reactive Metals (cations)

Noble Gas Family: Group 18 Unreactive (chemically inert) elements

Halogen Family: Group 17 Highly reactive (anions)